In an evolved packet system, there are two states for user equipment attaching to a network a connected state and an idle state. In the connected state, a network side device allocates radio resources to the user equipment for transmission of user plane data, and a data packet may be directly transmitted between the user equipment and the network device. However, in the connected state, the user equipment consumes power quickly and occupies more radio resources. Therefore, the network side device turns the user equipment to the idle state when there is no data transmission for a period of time. In the idle state, the network device releases the radio resources allocated to the user equipment, and the user equipment operates in a power saving mode. However, when the user equipment in the idle state needs to transmit data, the user equipment first needs to turn to the connected state. In the idle state, a location area that is of the user equipment and known by the network side device is called a tracking area list. The user equipment is paged in all cells in the tracking area list of the user equipment using a paging technology when the network side device needs to send signaling or data to the user equipment. After receiving a paging message sent to the user equipment, the user equipment makes a response, establishes a communications link to the network side device, and turns to the connected state. However, in other approaches, paging needs to be performed in a tracking area list of user equipment, and due to a large paging range of the tracking area list, paging efficiency is low and more paging resources are consumed.